Electrospinning has been employed to create various types of microscale and nanoscale tubes, often called microtubes or nanotubes. These are typically made from polymers and other materials suitable for electrospinning, and processes for their creation typically include coaxially spinning two materials and then extracting the center material to leave a hollow core and form a tube structure. The present invention improves on the art of microtubes and nanotubes by providing tubular structures that respond to applied pressure or electromagnetic fields. The response to mechanical stress or electromagnetic fields is a result of two components of the tubular structure, electroactive polymer and rheologic fluid. The structures will have many applications.
As a result of their shape and components, these tubular structures may find application as synthetic muscle fibers, sensors and actuators, nerve conduits and blood capillaries.
They might also find application as dry adhesives. A mass of spun fibers or tubes can be formed that somewhat mimics the hierarchical structures of fine fibrils on the feet of insects and other animals, for example, gecko lizards. These structures induce strong molecular forces and provide extraordinary adhesive strength, enabling them to support large loads and even climb and run on wet or dry molecularly smooth surfaces. This dry adhesion allows such animals to move on slippery surfaces against gravity as well as firmly attach onto and detach from rough substrates. The art of dry adhesion would benefit from the creation of structures that can mimic the dry adhesion of such animals. This could lead to the creation of spiderman suits and civilian and military clothing.
There is also a drive to provide protective fabrics for various applications, be it in clothing (e.g., bullet-proof clothing) or other protective coverings. The tubular structures of the present invention might be employed in such applications.